Bone production by osteoblasts and resorption by osteoclasts is critical for normal bone development and remodeling. Excessive resorption is a key pathogenic component in osteopenic conditions such as osteoporosis, arthritis, periodontitis and certain malignancies. Bone resorption is regulated by a complex system of hormones and locally-produced cytokines that stimulate osteoblasts and stromal cells to express Receptor Activator of NF-κB Ligand (RANKL), resulting in the differentiation and activation of osteoclasts. The processes by which osteoclast differentiation and activation occur are currently not well understood.
Regulators of osteoclastic resorption and bone production by osteoblasts are currently not well understood.